An IP phone terminal for calling by a communication using a packet is used.
When an incoming call from others is received by the IP phone terminal, a ring tone sounds and a user's attention is invited. This ring tone sounds from a built-in speaker. However, when the user is using a headset, it is usually the case that the ring tone sounds from the headset.
Incidentally, a technique to output the ring tone from both the headset and the speaker is disclosed (refer to Patent Document 1).
[Patent Document 1] JP-A 2003-169107 (KOKAI)